Sage probably benefits from their relationship up to the end of Crossroads being "fuck buddies to something more"/"very new", so the blow might be the least heartbreaking of the five. That isn't to say she isn't hurt and no longer has feelings for him of course, but despite ironically having anger issues she does carry it well enough.
Josy 100% takes it the worst, I won't even post her reaction here. It hurts the soul. Despite rejecting MC as much as possible in Episode 10, she can't bring herself to delete that photo from their first date.
Jill is pretty devastated, especially if we chose Bella over her. Her first real love was fucking around with other girls, it's gotta hurt. She tries to remain cordial with MC, show some maturity about the situation.
Maya "takes it well" because she's been disappointed all her life, and is unfortunately used to it. But MC is too big a presence in her life, means too much to her that she doesn't want to cut him out like Josy tries to. Even after hurting her like that, MC is still one of the best things that's ever happened to her.
Bella has been trying to fight her feelings all throughout Seasons 1 and 2, as the MC slowly finds his way into her heart. Everything seems to be against them: the age gap, being a (technically) married woman, becoming his teacher, her active encouragement of Jill and MC, it feels like it won't ever work. The thing about breaking up with her is that she finally let her guard down. She chose to believe it could work, that she could be happy despite the odds, and open herself up once again to the idea that someone that loves her. And then MC just leaves her, confirming all the doubts she had in the first place, and how stupid she must feel now. Brutal. And a smaller version of this happens if you fucked around with Cathy, Bella is more dignified here but she was on the cusp of accepting this whole thing, the hangout after tennis is what pushes it over the edge.
